This invention relates to a construction of a discharge electrode using pin-shaped electrodes, and more particularly, to a discharge electrode for gas discharge device in which said pin-shaped electrodes are effectively cooled in a gas flow and in which a stable glow discharge can be accomplished in the gas flow.
In the prior art, a known discharge electrode having pin-shaped electrodes is used in various gas discharge devices. For instance, in one form of this pin-shaped electrode, a predetermined length of a wire member is bent approximately into an L shape, one side of the L shape (post portion) being set upright on an insulating base plate and the other side (extension portion) being allowed to accomplish a required electric discharge.
However, in case such kind of pin-shaped electrode is used, for instance, on a 3-axis orthogonal type laser oscilating apparatus, the following problems occur.
(1) Since the end of the extension portion has such a form that is made merely by shearing a wire member, a local electric discharge occurs at this end, and thus it is difficult to allow a stable glow discharge. PA0 (2) Also, when the extension portion is allowed to coincide with the direction of the gas flow, the gas which has been heated by the base portion of the extension portion will flow towards to end thereof, and thus the cooling of the pin-shaped electrode will become insufficient.